In the prior art, various disclosures as shown by the following U.S. patents have been made of the type doorlock that can be carried from place to place and installed in a room without preparation or modification of a standard door, for engagement of a strike plate or similarly located portion of a door frame with the leading face of an inward-opening hinged door.
U.S. Pat. No. 936,164 to N. W. Reid on 10-5-09 showed a pivotal adjustment door fastener with a hook on one blade or arm and a pusher on another;
U.S. Pat. No. 1,079,860 to G. Kiehle disclosed the same general type drive with cotter-pin-in-hole adjustment and slidable band 13; evidently this could be used also with the door swinging the other way, 11-25-13.
U.S. Pat. No. 1,171,671 to F. T. Skogland, 2-15-16, showed a similar type fastener with toothed adjustment provision;
U.S. Pat. No. 1,971,440 to O. Aubertin, 8-28-34, showed a two-piece unit with coarse slots in a bent-over portion for engaging the front end of the other piece;
U.S. Pat. No. 4,169,619 to J. H. McCracken, 10-2-70, showed another attachment device, this one with a cushion. FIGS. 8-10 showed a toothed slot adjustment.
However, none of the disclosures provided the combination of advantage of the system of applicant's invention, as indicated by the following and other objects.
A principal object is to provide a system as described that is easy to manufacture, requiring only two stamping operations for the basic parts;
Further objects are to provide a system as described that is easy to apply to a door, is substantially self-adjusting, and is strong and reliable;
Yet further objects are to provide a system as described that has for the two basic parts a latching mechanism in duplicate (or greater numbers) for strength, but without complexity of construction or of operation.
Still further objects are to provide a system as described that is adapted for installation or removal in darkness by feeling the relation of the parts, which are purposefully made different.